Police have broken up a terror ring plotting an attack in France after arresting seven suspects in Strasbourg and Marseille, Interior Minister Bernard Cazeneuve said on Monday.
The arrests of seven people -- of French, Moroccan and Afghan origin -- "enabled us to prevent a long-planned terror attack on our soil," Cazeneuve told a televised news conference.
He said the investigation would show whether "the foiled attack was a coordinated attack aiming to target several sites simultaneously on our soil."
The raids were carried out overnight Saturday to Sunday in the eastern city of Strasbourg and Marseille in the south following an eight-month investigation by security services.
"Credible information made these arrests necessary," one security source told AFP earlier, asking not to be named because they were not authorised to speak on the case.
Cazeneuve linked the arrests to raids carried out shortly before the Euro 2016 football championship hosted by France in June.
The country remains in a state of emergency a year after attacks by Islamic State jihadists on Paris that left 130 people dead.
Cazeneuve said 418 people had been arrested for suspected links to terror networks since the start of the year.
Strasbourg has been on high alert ahead of the opening of its Christmas market, with local officials warning it could be suspended or cancelled if there were serious threats.